This invention relates to a trainable equalizer.
On training an equalizer, it is conventional to transmit test signals from a transmitter prior to transmission of data signals to a receiver where the equalizer is located. For data signals and consequently test signals transmitted at a high speed compared with the frequency band, complicated procedures have been required for the training. For test signals subjected to a serious distortion during transmission, it has been difficult to duly train the equalizer. In order to train the equalizer with seriously distorted test signals, the transmitter may successively produce as the test signals a tone signal of the carrier frequency, a burst signal, and a pseudo-noise series or train of a predetermined pulse pattern a predetermined time after the burst signal. It is indispensable in the receiver to detect the burst signal, to find the end thereof, and to generate the predetermined time thereafter a pseudo-noise train of the predetermined pulse pattern. Furthermore, it has generally been necessary to set up correct timing between the pseudo-noise train generated in the receiver and that transmitted from the transmitter. This has inevitably resulted in a long period of time required to accomplish the training.